An Unusual Suspect for a Traumatic Arteriovenous Fistula in the Left Vertebral Artery

Abstract

This case study discusses an unusual vertebral arteriovenous fistula of a patient with no history of an invasive medical procedure or underlying genetic disorders. The patient is a 54-year-old female with a history of tinnitus for 6 months behind the left ear prior to coming to the vascular laboratory. There was a connection between the left vertebral artery and the vertebral vein, which showed a mosaic pattern with a high velocity. The spectral Doppler waveform in the vertebral vein post the unintended anastomosis showed an arterialized venous Doppler waveform, confirming that the area of the interest was indeed an arteriovenous fistula. The image of the screening computed tomography performed on the same day did not show this connection or dilated venous system, possibly because of the small size of the fistula. A published literature suggests hyperextension as a possible suspect. There are a few test modalities that can identify an arteriovenous fistula, but ultrasound maybe the most desirable due to the fact that it does not involve an invasive procedure or a contrast dye. It is very important for a sonographer to learn the advanced information such as how to identify a true arteriovenous fistula with the analysis of Doppler waveform in the vein post the anastomosis. In doing so, it will increase the sonographer’s knowledge as well as promoting the field of ultrasound overall.